Zhengzhou balloon recruitment

Insert the straw into the milk box to blow air into it, and let it go quickly, and the milk will be ejected from the straw; The reason for milk injection is strong internal pressure; The reason for the increase of pressure in the box is caused by blowing air into it, that is to say, the pressure of gas is related to the quality of gas; Similarly, put the blown balloon near the stove, and after a while, the balloon will burst; That is, the balloon burst is also due to the increase of internal pressure, that is, the temperature, so the gas pressure is also related to the temperature.

(1) Blow air into the bottle with a thin tube, and the air quality in the bottle becomes larger, so the air pressure in the bottle becomes larger and it is released quickly. It is observed that the water column in the thin glass tube will rise to the position of a;

(2) After the outer wall of the flask is coated with a layer of alcohol, the alcohol will evaporate and absorb heat from the flask, resulting in the decrease of gas temperature and pressure in the flask.

(3) Atmospheric pressure decreases with the increase of altitude; Therefore, if the experimental flask (1) is taken to the top of the mountain, the water column in the tube will be higher than the position at A, because the air pressure at the top of the mountain is lower than the standard atmospheric pressure (assuming the temperature is constant).

(4) a, judging the current by using a conversion method according to the brightness of the small bulb;

B. Explore the factors that affect the magnetic induction intensity of electromagnet, judge the magnetic induction intensity of electromagnet by the number of nails attracted by electromagnet, and use transformation method;

C, when exploring "",the data are obtained through many measurements, and then the equilibrium conditions are obtained through analyzing the data, and induction is adopted;

D, measure the mechanical efficiency of the pulley block with the control variable method.

So, the answer is: quality; Temperature; (1) increase; (2) reduce; (3) higher than; The pressure at the top of the mountain is lower than the standard atmospheric pressure;

(4)A、b。